Method of producing brush-like grind stone, the brush-like grind stone, and brush for grind machine

ABSTRACT

In the manufacture of a brush-shaped grindstone ( 3 ), embedding holes ( 310 ) are formed in a grinding element holding surface ( 311 ) of a holder ( 31 ) in mutually separated positions. A base end side of a plurality of wire-shaped grinding elements ( 32 ), formed such that a composite yarn composed of inorganic filaments is impregnated and hardened with a resin, is aligned, and rod assemblies ( 320 ) are thereafter formed by fixing the base end side of the plurality of wire-shaped grinding elements ( 32 ) with adhesive ( 71 ) in holes ( 60 ) of a die material ( 6 ), which is formed to have substantially the same size as the embedding holes ( 310 ) of the holder ( 31 ). The rod assemblies ( 320 ) are thereafter embedded in the embedding holes ( 310 ) of the holder ( 32 ), and fixed with adhesive ( 72 ). Whereby, removing burrs from a precision work component, performing polishing, and the like can be carried out with good efficiency and high precision.

TECHNICAL FIELD

The present invention relates to a manufacturing method for abrush-shaped grindstone for deburring and polishing, to a brush-shapedgrindstone manufactured with this method, and to a polisher brush thatuses this brush-shaped grindstone.

BACKGROUND ART

Precision components primarily used in automobile parts, aircraft parts,and the like are worked with precision and high accuracy primarily bymeans of numerically controlled lathes, numerically controlled millingmachines, machining centers, robots, special purpose machines, and otherautomatic machines, using end mills, drills, dies, taps, grindstones,and other tools. However, after these precision machines have worked,burrs, work marks, tool marks, or the like are always present, sopost-working is required to remove these. Such post-working toolsconventionally involve the use of nylon brushes with abrasive grain,brass brushes, wire brushes, shot blasts, barrels, paper, and the like.Much of the final finishing process further involves manual work.

However, nylon brushes with abrasive grains, brass brushes, wirebrushes, shot blasts, barrels, paper, or the like, used in conventionalworking have drawbacks in that removal efficiency of these burrs, workmarks, and the like, and the polishing efficiency is poor. Conventionalpost-working tools have poor working accuracy, and have drawbacks inthat burrs, work marks, and the like are left, and there is greatvariation in the manufacturing quality after working.

In the particular case of deburring that involves precision components,it is possible that defective operation of sliding portions, blockage ofhydraulic pathways, shorting of electrical circuits, oil leaks, andother critical flaws will result if parts that have burrs left behind orthat have variation in manufacturing quality after burr removal areassembled into an apparatus.

In conventional practice, therefore, burrs are primarily removed fromprecision components by hand in a separate step away from the automatedline, total inspection is performed thereafter, and it is thereforedifficult to automate burr removal.

DISCLOSURE OF INVENTION

An object of the present invention is to provide a brush-shapedgrindstone and a manufacturing method thereof whereby burrs, work marks,and the like can be removed from precision work components, polishingcan be performed, and other processes can be conducted with goodefficiency and high accuracy.

Another object of the present invention is to provide a brush forpolishers that are suitable for automating the removal of burrs, workmarks, and the like, and for automating polishing operations in which abrush-shaped grindstone is used.

To solve the drawbacks described above, according to the presentinvention, there is provided a manufacturing method for a brush-shapedgrindstone having wire-shaped grinding elements formed such that acomposite yarn composed of inorganic filaments is impregnated andhardened with a resin, and also having a holder for holding base endsides of a plurality of wire-shaped grinding elements on a grindstoneholding surface, comprising steps of forming a plurality of embeddingholes that open on the grindstone holding surface in isolated positions;forming rod assemblies by bringing a plurality of wire-shaped grindingelements together; and embedding base end sides of the rod assemblies inthe embedding holes and fixing with adhesive.

In the manufacturing method for the brush-shaped grindstone of thepresent invention, the rod assemblies are separated from each otherbecause the plurality of embedding holes are formed in isolatedpositions on the grindstone holding surface of the holder. Thegrindability is therefore excellent because the shavings are efficientlyexpelled during grinding work and the heat dissipating effect is high.Removal of burrs and work marks from the precision work component,polishing, and other processes can further be performed with goodefficiency and high accuracy. The cost can also be reduced because highgrinding performance can be obtained with a small number of rods.

Furthermore, in the case of nylon filaments containing abrasive grain,the nylon filaments can be prevented from unraveling by folding base endsides to provide thickness and then embedding the filaments in holes inthe holder, but when wire-shaped grinding elements composed of inorganicfilaments are used, the base end sides cannot be folded as can nylonfilaments containing abrasive grain because wire-shaped grindingelements composed of inorganic filaments break when folded. According tothe present invention, however, the wire-shaped grinding elements do notunravel, because the base end sides of the rod assemblies are fixedinside the embedding holes of the holder with adhesive. The brush-shapedgrindstone can be efficiently manufactured because a plurality of rodassemblies are batch manufactured, and these are inserted in successionin the embedding holes of the holder and fixed with adhesive. Theconfiguration is one in which large numbers of wire-shaped grindingelements are subdivided as rod assemblies and fixed, so the safety ishigh because the wire-shaped grinding elements remain mostly in place.Even when the grinding performance is increased with the cross-sectionsof the wire-shaped grinding elements in an elliptical shape, theorientation of the cross-sectional shapes thereof are random, so thegrinding performance can be further improved and the roughness offinished surface can be improved.

In the present invention, for example, round holes are formed as theembedding holes in the holder, and when the rod assemblies are formed,the plurality of wire-shaped grinding elements are roundly bundled.

In the present invention, grooves are formed as the embedding holes inthe holder, and when the rod assemblies are formed, the plurality ofwire-shaped grinding elements may be flatly aligned.

In the present invention, the wire-shaped grinding elements can take aconfiguration in which the inorganic filaments form a composite yarnwithout being twisted, or a configuration in which the inorganicfilaments form a composite yarn having been twisted. Of theseconfigurations, when inorganic filaments form a composite yarn havingbeen twisted, an advantage is obtained whereby leading ends of thewire-shaped grinding elements are resistant to splitting.

In the present invention, the cross-sections of the wire-shaped grindingelements can take a configuration in which the shape is substantiallycircular, or a configuration in which the shape is flat. When thecross-sections of the wire-shaped grinding elements are flat, pluggingis less likely to occur during burr removal and polishing work than withthe configuration in which the shape of the cross-section issubstantially circular. An advantage is obtained whereby flexibility isexhibited in the wire-shaped grinding elements, and breaking isminimized. When the cross-sections of the wire-shaped grinding elementsare flat, the ratio of flatness represented by L/T is preferably 1.6 to15, but is more preferably in a range of 1.6 to 10, where L is the majordiameter of the cross-section, and T is the minor diameter of thecross-section.

The brush-shaped grindstone in which the present invention is appliedmay, for example, be used as a polisher brush in which the holder isfixed with screws on an interior side of a brush case so that free endsof the wire-shaped grinding elements protrude from a lower end portionof the brush case.

In this case, a spindle extended inside of the brush case in an axialdirection thereof, and guide holes extended in the form of grooves in aperipheral wall of the brush case in the axial direction of the brushcase; an axle hole in which the spindle is fitted, and screw holes thatextend from an external peripheral surface of the holder to the axlehole are formed in the holder; and the screws are secured in the screwholes so as to be attached to the external peripheral side of the brushcase and to pass completely through the guide holes in a state in whichleading end portions of screw shafts make contact with an externalperipheral surface of the spindle.

In a polisher brush thus configured, when the brush-shaped grindstone isinserted from a holder side into an interior side of the brush case, thespindle is inserted through the axle hole of the holder. In this state,the screws are inserted into guide holes from an external peripheralside of the brush case until the leading end portions of the screwshafts come in contact with the external peripheral surface of thespindle, and axle portions of the screws tighten in the screw holes ofthe holder. As a result, the holder is fixed onto the spindle inside thebrush case. If the screw is loosened, the protruding length of thewire-shaped grinding elements at the lower end portion of the brush casecan be adjusted by moving the holder along the spindle. The axle portionof the screw is guided at this time in the guide holes, and thebrush-shaped grindstone moves along the guide holes. The protrudinglength of the wire-shaped grinding elements at the lower end portion ofthe brush case can therefore be easily adjusted.

The holder is fitted within the brush case, and because the spindle isfitted into the axle hole of the holder, the holder does not tilt insidethe case even in the cased of considerable dimensional tolerance betweenan outer diameter of the holder and an inner diameter of the brush case.There is therefore no variation in the protruding length of thewire-shaped grinding elements. Because the spindle is fitted into theaxle hole of the holder, the holder can remain fixed at a centerposition of the brush case even with considerable dimensional tolerancebetween the outside diameter of the holder and the inside diameter ofthe brush case. Thus, because the dimensional tolerance between theoutside diameter of the holder and the inside diameter of the brush caseneed not be strict, even when shavings enter the space between these,the protruding length of the wire-shaped grinding elements at the lowerend portion of the brush case can be easily adjusted because the holdercan be smoothly moved inside the brush case by loosening the screw.

Even when the wire-shaped grinding elements attempt to escape to theexternal peripheral side as the polisher brush is rotated to performpolishing or the like, they bump against the interior surface of theperipheral wall of the brush case and are held back, and when theelements attempt to escape to the interior peripheral side, they bumpagainst the external peripheral surface of the spindle and are heldback. As a result, there is no difference in the extent of escapebetween the wire-shaped grinding elements positioned on an externalperipheral side and the wire-shaped grinding elements positioned on aninterior peripheral side. The situation in which the wire-shapedgrinding elements positioned on the interior peripheral side become lessabrasive can therefore be avoided because no difference in rigidity isexhibited between the wire-shaped grinding elements positioned on theexternal peripheral side and the wire-shaped grinding elementspositioned on the interior peripheral side. The working precision canalso be improved because the wire-shaped grinding elements are uniformlyabraded. Since no variation occurs in the length (strand length) of thewire-shaped grinding elements from the holder, the change inconformability and grindability due to this effect is reduced, so theworking precision is stable.

In the present invention, the surrounding area where the leading ends ofscrew shafts contact on the external peripheral surface of the spindleis preferably a flat surface.

The spindle is normally formed from a round rod or circular pipe, andthe leading end portions of the screw shafts are brought into contactwith the external peripheral surface thereof. Fashioning the surroundingarea in contact with the leading end portions of the screw shafts in aflat surface prevents the leading end portions of the screw shafts fromshifting on the external peripheral surface of the spindle even when thepolisher brush rotates at high speed, because the leading ends of thescrew shaft make stable contact with the external peripheral surface ofthe spindle. A space is further formed between the external peripheralsurface of the spindle and the internal peripheral surface of the axlehole of the holder in the portion in which this flat surface is formedbecause the surrounding area where the leading end portions of the screwshafts make contact is flat. Therefore, even when the dimensionaltolerance between the outside diameter of the spindle and the insidediameter of the axle hole is strict, and the tilt and eccentricity ofthe holder are more strictly prevented, problems do not arise wherebythe holder inside the brush case ceases moving due to the shavings thatenter between the external peripheral surface of the spindle and theinternal peripheral surface of the axle hole. Even if the spindle isdamaged by contact with the leading end portion of the screw, the holdercan be smoothly moved inside the brush case because the holder is notprevented from moving inside the brush case if the damage is to the flatsurface.

In the present invention, the guide holes preferably extend parallel inthe axial direction on the peripheral wall of the brush case. Such aconfiguration allows guide holes to easily be formed even if theperipheral wall of the brush case is cylindrical.

The guide holes may also be configured so as to extend in a directiondiagonal to the axial direction on the peripheral wall of the brushcase. When the guide holes that guide the brush-shaped grindstone extendon the peripheral wall of the brush case in a direction diagonal to theaxial direction thereof, the position in the axial direction of thebrush-shaped grindstone within the brush case can be easily adjusted insmall increments. The stiffness of the wire-shaped grinding elements, inother words, the grindability and conformability can easily and quicklybe adjusted to an optimal state because the protruding length of thefree ends of the wire-shaped grinding elements can easily and quickly beadjusted to an optimal length. This provides an advantage in that themovement of the brush-shaped grindstone is smooth even when thebrush-shaped grindstone does not easily move inside the brush case,because force is applied to the brush-shaped grindstone in the directionin which the brush-shaped grindstone rotates about the axis line.

In the present invention, when the guide holes extend parallel in theaxial direction on the peripheral wall of the brush case, or when theguide holes are configured so as to extend in a direction diagonal tothe axial direction on the peripheral wall of the brush case, aprojecting portion that projects to the external peripheral side ispreferably attached to the lower end side of the spindle.

With this configuration, even when the wire-shaped grinding elementsattempt to escape to the external peripheral side when the polisherbrush is rotated to perform polishing or the like, they bump against theinterior surface of the peripheral wall of the brush case and are heldback, and if the elements attempt to escape to the interior peripheralside, they bump against the external peripheral side of the projectingportion disposed on the spindle and are held back. As a result, there isno difference in the extent of escape between the wire-shaped grindingelements positioned on the external peripheral side and the wire-shapedgrinding elements positioned on the interior peripheral side. Thesituation in which the wire-shaped grinding elements positioned on theinterior peripheral side become less abrasive can therefore be avoidedbecause no difference in rigidity is exhibited between the wire-shapedgrinding elements positioned on the external peripheral side and thewire-shaped grinding elements positioned on the interior peripheralside. The working precision can also be improved because the wire-shapedgrinding elements are uniformly abraded. Since no variation occurs inthe length (strand length) of the wire-shaped grinding elements from theholder, the change in conformability and grindability due to this effectis reduced, so the working precision is stable. At this point, if theprojecting portion is attached with screws and screw stops so as toallow easy removal, the work of replacing worn wire-shaped grindingelements can easily be performed.

In the present invention, when the guide holes extend parallel in theaxial direction on the peripheral wall of the brush case, a projectingportion that projects to the external peripheral side is preferablyattached to the lower end side of the spindle, a plurality ofprotrusions extended in a radial manner toward the external peripheralside are formed on an external peripheral side of the projectingportion, and the wire-shaped grinding elements are evenly positionedbetween the protrusions.

With this configuration, even when the wire-shaped grinding elementsattempt to escape to the external peripheral side, they bump against theinterior surface of the peripheral wall of the brush case and are heldback. When the wire-shaped grinding elements attempt to escape to theinterior peripheral side, they bump against the external peripheral sideof the projecting portion disposed on the spindle and are held back, andthe range of escape is narrowed by the protrusions. As a result, thereis no difference in the extend of escape between the wire-shapedgrinding elements positioned on the external peripheral side and thewire-shaped grinding elements positioned on the interior peripheralside. The situation in which the wire-shaped grinding elementspositioned on the interior peripheral side become less abrasive cantherefore be avoided because no difference in rigidity is exhibitedbetween the wire-shaped grinding elements positioned on the externalperipheral side and the wire-shaped grinding elements positioned on theinterior peripheral side. The working precision can also be improvedbecause the wire-shaped grinding elements are uniformly abraded. Sinceno variation occurs in the length (strand length) of the wire-shapedgrinding elements from the holder, the change in conformability andgrindability due to this effect is reduced, so the working precision isstable. Variation in the rigidity of the wire-shaped grinding elementscan be reduced in the peripheral direction as well because theprotrusions prevent the wire-shaped grinding elements from escaping inthe peripheral direction. At this point, if the projecting portion isattached with screws and screw stops so as to allow easy removal, thework of replacing worn wire-shaped grinding elements can easily beperformed.

In the present invention, when the guide holes extend parallel in theaxial direction on the peripheral wall of the brush case, a plurality ofprotrusions extended in a radial manner toward the external peripheralside are preferably attached to the spindle, and the wire-shapedgrinding elements are evenly positioned between the protrusions.

With this configuration, even when the wire-shaped grinding elementsattempt to escape to the external peripheral side, they bump against theinterior surface of the peripheral wall of the brush case and are heldback. When the wire-shaped grinding elements attempt to escape to theinterior peripheral side, they bump against the external peripheral sideof the spindle and are held back, and the range of escape is narrowed bythe protrusions. As a result, there is no difference in the extend ofescape between the wire-shaped grinding elements positioned on theexternal peripheral side and the wire-shaped grinding elementspositioned on the interior peripheral side. The situation in which thewire-shaped grinding elements positioned on the interior peripheral sidebecome less abrasive can therefore be avoided because no difference inrigidity is exhibited between the wire-shaped grinding elementspositioned on the external peripheral side and the wire-shaped grindingelements positioned on the interior peripheral side. The workingprecision can also be improved because the wire-shaped grinding elementsare uniformly abraded. Since no variation occurs in the length (strandlength) of the wire-shaped grinding elements from the holder, the changein conformability and grindability due to this effect is reduced, so theworking precision is stable. Variation in the rigidity of thewire-shaped grinding elements can be reduced in the peripheral directionas well because the protrusions prevent the wire-shaped grindingelements from escaping. At this point, if the projecting portion isattached with screws and screw stops so as to allow easy removal, thework of replacing worn wire-shaped grinding elements can easily beperformed.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram depicting the state in which the upper portion ofthe brush-shaped grindstone is inserted and fixed in the interior of thebrush case in a polisher brush wherein the present invention has beenapplied;

FIG. 2 is a cross-sectional view through a section in which the polisherbrush depicted in FIG. 1 is fixed in place with screws;

FIG. 3 is a bottom view of the polisher brush depicted in FIG. 1;

FIG. 4 is an exploded perspective view depicting the state in which thepolisher brush depicted in FIG. 1 is disassembled into a brush case anda brush-shaped grindstone;

FIGS. 5 to (D) are, respectively, a diagram depicting the state in whichthe surrounding region where the guide holes open is made into a flatsurface on the external peripheral surface of the peripheral wall of thebrush case in the polisher brush depicted in FIG. 1; a diagram depictingthe state in which the surrounding region where the leading end portionsof the screw shaft portions make contact on the external peripheralsurface of the spindle; a longitude-sectional view depicting an enlargedview of the portion that stops the screw; and a cross-sectional viewdepicting an enlarged view of the portion that stops the screw;

FIGS. 6(A) to (E) are diagrams depicting the manufacturing method forthe brush-shaped grindstone depicted in FIG. 1;

FIGS. 7(A) and (B) are, respectively, a diagram and a bottom view thatschematically depict the polisher brush related to embodiment 2 of thepresent invention;

FIGS. 8(A) and (B) are, respectively, a diagram and a bottom view thatschematically depict the polisher brush related to embodiment 3 of thepresent invention;

FIGS. 9(A) and (B) are, respectively, a diagram and a bottom view thatschematically depict the polisher brush related to embodiment 4 of thepresent invention;

FIG. 10 is an exploded perspective view depicting the state in which thepolisher brush related to embodiment 5 is disassembled into a brush caseand a brush-shaped grindstone;

FIGS. 11(A), (B), and (C) are diagrams depicting the structure of thebrush-shaped grindstone related to other embodiment 1 of the presentinvention; and

FIGS. 12(A), (B), and (C) are diagrams depicting the structure of thebrush-shaped grindstone related to other embodiment 2 of the presentinvention.

(Symbols)

-   1 polisher brush-   2 cylindrical brush case-   3, 3A, 3B, 3C, 3E, 3F brush-shaped grindstones-   6 die material-   20 peripheral wall-   21 connecting shaft for driving-   25 spindle-   26, 27 guide holes-   30 axle hole-   31 holder-   32 wire-shaped grinding element-   33 free end of the wire-shaped grinding element-   36, 37 screw holes-   41,42 screw-   60 hole of the die material-   71,72 adhesive-   310 embedding hole-   311 grindstone holding surface-   320 rod assembly-   L axis line

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiments of the present invention will now be described withreference to the drawings.

Embodiment 1

FIG. 1 is a diagram depicting a state in which an upper portion (holderside) of a brush-shaped grindstone is inserted and fixed in an interiorof a brush case in a polisher brush wherein the present invention hasbeen applied. FIG. 2 is a cross-sectional view through a section inwhich the polisher brush depicted in FIG. 1 is fixed in place withscrews. FIG. 3 is a bottom view of the polisher brush depicted inFIG. 1. FIG. 4 is an exploded perspective view depicting a state inwhich the polisher brush depicted in FIG. 1 is disassembled into thebrush case and the brush-shaped grindstone. FIGS. 5(A), (B), (C), and(D) are, respectively, a diagram depicting a state in which asurrounding region where the guide holes open is made into a flatsurface on an external peripheral surface of a peripheral wall of thebrush case in the polisher brush depicted in FIG. 1; a diagram depictinga state in which a surrounding region where a leading end portion of anaxle portion of a screw makes contact on an external peripheral surfaceof the spindle; a longitude-sectional view depicting an enlarged view ofa portion that stops the screw; and a cross-sectional view depicting anenlarged view of the portion that stops the screw.

As shown in FIGS. 1 to 4, the polisher brush 1 of the present embodimentcomprises a cylindrical metal brush case 2 that comprises a connectingshaft 21 for driving on an upper portion; a brush-shaped grindstone 3whose upper portion is inserted into this brush case 2; and screws 41and 42 for fixing this brush-shaped grindstone 3 in a predeterminedposition inside the brush case 2.

In the present embodiment, an upper end portion of a round virgatespindle 25 is fixed in the center of an upper bottom portion of thebrush case 2, and this spindle 25 extends in a direction of an axis lineL concentrically with a peripheral wall 20 in the interior side of thebrush case 2. On the peripheral wall 20 of the brush case 2, guide holes26 and 27, extended in the form of a groove in a direction parallel tothe direction of the axis line L thereof, are formed inpoint-symmetrical positions on opposite sides of the axis line L. In thepresent invention, the brush case 2 is composed such that the peripheralwall 20 is aluminum and the spindle 25 is stainless steel.

In the present embodiment, the brush-shaped grindstone 3 comprises acylindrical metal holder 31 wherein a plurality of embedding holes 310are formed in isolated positions on a grinding element holding surface311, and rod assemblies 320 whose base end portions are embedded in theembedding holes 310. The rod assemblies 320 comprise a large number ofwire-shaped grinding elements 32, obtained such that a composite yarncomposed of inorganic filaments such as alumina filaments is impregnatedand hardened with a binder resin. An axle hole 30 through which thespindle 25 is inserted is formed in a center of the holder 31. A pair ofscrew holes 36 and 37 is formed in a peripheral wall of the holder 31 inpoint-symmetrical positions on the opposite sides of the axis line L,and these screw holes 36 and 37 reach from the external peripheralsurface of the peripheral wall of the holder 31 to the axle hole 30.

Thus, the brush-shaped grindstone 3 used in the present embodiment hasexcellent grindability because large numbers of the wire-shaped grindingelements 32 are subdivided as roundly bundled rod assemblies 320 andfixed with adhesive in the plurality of embedding holes 310 of theholder 31, so the shavings are efficiently expelled during grinding workand the heat dissipating effect is high. Removal of burrs and work marksfrom the precision work component, polishing, and other processes canfurther be performed with good efficiency and high accuracy. The costcan also be reduced because high grinding performance can be obtainedwith a small number of rods. Adopting a configuration in which largenumbers of the wire-shaped grinding elements 32 are subdivided and fixedmakes it possible to prevent the wire-shaped grinding elements 32 fromunraveling. This configuration is therefore advantageous in that it ishighly safe.

When assembling the polisher brush 1 using the brush-shaped grindstone 3and the brush case 2 configured in this manner, the spindle 25 is fittedin the axle hole 30 of the holder 31, the upper portion (on a side ofthe holder 31) of the brush-shaped grindstone 3 is inserted inside thebrush case 2, the screws 41 and 42 are thereafter passed through theguide holes 26 and 27 from the external peripheral side of the brushcase 2, as shown in FIGS. 5(C) and (D), and the screws 41 and 42 arerespectively screwed into the screw holes 36 and 37 of the holder 31. Atthis point, the screws 41 and 42 are tightened until the leading endportions of the axle portions of the screws 41 and 42 make contact withthe external peripheral surface of the spindle 25. As a result, theholder 31 is fixed onto the spindle 25 of the brush case 2 by way of thescrews 41 and 42 inside the brush case 2.

The screws 41 and 42 are shallowly screwed into the screw holes 36 and37 of the holder 31 through the guide holes 26 and 27 of the brush case2, and, in this state, the position of the brush-shaped grindstone 3inside the brush case 2 can be adjusted in the direction of the axisline L by moving the brush-shaped grindstone 3 inside the brush case 2in the direction of the axis line L. A protruding length of a free end33 of the wire-shaped grinding elements 32 at a lower end portion 29 ofthe brush case 2 can be adjusted, so the stiffness of the wire-shapedgrinding elements 32, in other words, the grindability andconformability can be optimized.

Adopting such a fixed configuration by way of the screws 41 and 42entails having flat surfaces 260 and 270 on an external peripheralsurface of the peripheral wall 20 of the brush case 2 in the areasurrounding the openings of the guide holes 26 and 27, as shown in FIGS.5(A), (C), and (D). A surrounding area where the leading end portions ofthe axle portions of the screws 41 and 42 make contact on the externalperipheral surface of the spindle 25 is a flat surface 250, as shown inFIGS. 5(B), (C), and (D).

The polisher brush 1 assembled in this manner is linked to a polisher byway of a connecting shaft 21 for driving, which protrudes at a topportion of the brush case 2. The polisher brush 1 is then rotatablydriven about the axis line L to remove all types of burrs and performpolishing work. Here, the polisher brush 1 is not limited to rotarymotion, but reciprocating action, oscillating action, swinging action,or a combination of these actions may be used to conduct motion. Themovement may also be combined with motion that vertically moves thebrush 1 for polishing in the direction of the axis line L.

As such burr removal and polishing work is performed, the wire-shapedgrinding elements 32 also abrade as such, and the protruding length ofthe wire-shaped grinding elements 32 at the lower end portion 29 of thebrush case 2 becomes shorter. Excellent burr removal and polishing workcannot be performed in this situation, so the protruding length of thewire-shaped grinding elements 32 at the lower end portion 29 of thebrush case 2 must be adjusted and the stiffness of the wire-shapedgrinding elements 32, in other words, the grindability andconformability must be adjusted.

This adjustment operation entails loosening the screws 41 and 42, movingthe brush-shaped grindstone 3 in the direction of the axis line L insidethe brush case 2, and shifting the position of the brush-shapedgrindstone 3 downward in direction of the axis line L inside the brushcase 2. The protruding length of the free end 33 of the wire-shapedgrinding elements 32 at the lower end portion 29 of the brush case 2 cantherefore again be adjusted to an optimal length.

The brush-shaped grindstone 3 at this time moves in the brush case 2along the guide holes 26 and 27, because the screws 41 and 42, which arescrewed into the screw holes 36 and 37 of the brush-shaped grindstone 3through the guide holes 26 and 27 from the external peripheral side ofthe brush case 2, are guided by the guide holes 26 and 27. As a result,in the present embodiment the screws 41 and 42 can conveniently be usedto guide the brush-shaped grindstone 3 when it is moved along the guideholes 26 and 27, and to fix the brush-shaped grindstone 3 in apredetermined position within the brush case 2.

In the present embodiment, the holder 31 is fitted into the brush case2, and the spindle 25 is fitted into the axle hole 30 of the holder 31.As a result, the holder 31 does not tilt inside the brush case 2 evenwith considerable dimensional tolerance between an outer diameter of theholder 31 and an inner diameter of the brush case 2. There is thereforeno variation in the protruding length of the wire-shaped grindingelements 32 at the lower end portion 29 of the brush case 2.Furthermore, the depth of cutting of the wire-shaped grinding elements32 into the work is fixed, so the precision during grinding is improved.

The holder 31 is fitted into the brush case 2, but because the spindle25 is fitted into the axle hole 30 of the holder 31, the holder 31remains fixed in the center position of the brush case 2 even withconsiderable dimensional tolerance between the outside diameter of theholder 31 and the inside diameter of the brush case 2. There is,therefore, no runout during rotation. Furthermore, the dimensionaltolerance between the outside diameter of the holder 31 and the insidediameter of the brush case 2 need not to be strict. Thus, even whenshavings enter a space between the holder 31 and the brush case 2, theprotruding length of the wire-shaped grinding elements 32 at the lowerend portion 29 of the brush case 2 can be easily adjusted because theholder 3 can be smoothly moved inside the brush case 2 by loosening thescrews 41 and 42.

In the present embodiment, when the wire-shaped grinding elements 32attempt to escape to an external peripheral side, they bump against aninterior surface of the peripheral wall 20 of the brush case 2 and areheld back, and when the elements attempt to escape to an interiorperipheral side, they bump against the external peripheral side of thespindle 25 and are held back. As a result, there is no leeway thatallows easy escape between the wire-shaped grinding elements 32positioned on the external peripheral side and the wire-shaped grindingelements 32 positioned on the interior peripheral side. The situation inwhich the wire-shaped grinding elements 32 positioned on the interiorperipheral side become less abrasive can therefore be avoided because nodifference in rigidity is exhibited between the wire-shaped grindingelements 32 positioned on the external peripheral side and thewire-shaped grinding elements 32 positioned on the interior peripheralside. The working precision can also be improved because the wire-shapedgrinding elements 32 are uniformly abraded. Since no variation occurs inthe length (strand length) of the wire-shaped grinding elements 32 fromthe holder 31, the change in conformability and grindability due to thiseffect is reduced, so the working precision is stable.

In the present embodiment, the area surrounding the openings of theguide holes 26 and 27 has flat surfaces 260 and 270 on the externalperipheral surface of the peripheral wall 20 of the brush case 2. Inother words, heads of the screws 41 and 42 are positioned in the areasurrounding the openings of the guide holes 26 and 27 on a circular-arcexternal surface of the peripheral wall 20 of the brush case 2. In thepresent embodiment, the heads to the screws 41 and 42 can be preventedfrom protruding far out on the external peripheral surface of theperipheral wall 20 because the area surrounding the openings of theguide holes 26 and 27 has flat surfaces 260 and 270. Even when thepolisher brush 1 rotates at high speed about the axis line L, wind noiseand the like can be reduced and the safety improved.

In the present invention, the surrounding area where the leading endportions of the axle portions of the screws 41 and 42 make contact onthe external peripheral surface of the spindle 25 is the flat surface250. In other words, the spindle 25 is shaped as a round bar, and theleading end portions of the screws 41 and 42 make contact on theexternal peripheral surface. In the present embodiment, the leading endportions of the screws 41 and 42 stably make contact with the externalperipheral surface of the spindle 25 because the surrounding area wherethe leading end portions of the screws 41 and 42 make contact is a flatsurface 250. The leading end portions of the screws 41 and 42 areprevented from shifting on the external peripheral surface of thespindle 25 even when the polisher brush 1 rotates at high speed. A spaceis further formed between the external peripheral surface of the spindle25 and the internal peripheral surface of the axle hole 30 of the holder31 in the portion in which this flat surface 250 is formed because thesurrounding area where the leading end portions of the screws 41 and 42make contact on the external peripheral surface of the spindle 25 is aflat surface 250. Therefore, even when the dimensional tolerance betweenthe outside diameter of the spindle 25 and the inside diameter of theaxle hole 30 is strict, and the tilt and eccentricity of the holder 31is more strictly prevented, problems do not arise whereby the holder 31inside the brush case 2 ceases moving due to the shavings that enterbetween the external peripheral surface of the spindle 25 and theinternal peripheral surface of the axle hole 30. Even if the spindle 25is damaged by contact made by the leading end portions of the screws 41and 42, the holder 31 can be smoothly moved inside the brush case 2because the holder 31 is not prevented from moving inside the brush case2 if the damage is to the flat surface 250.

(Manufacturing Method for Brush-Shaped Grindstone 3)

FIGS. 6(A) to (E) are diagrams depicting the manufacturing method forthe brush-shaped grindstone depicted in FIG. 1.

In the present embodiment, manufacturing the brush-shaped grindstone 3used in the polisher brush 1 entails forming embedding holes 310comprising a plurality of round holes in isolated positions in theperipheral direction on the grindstone holding surface 311 of the holder31, as shown in FIG. 3 in connection with the present embodiment.

A plurality of wire-shaped grinding elements 21 are roundly bundled inthe base end sides to form rod assemblies 320, and the base end sides ofthe rod assemblies 320 are embedded in embedding holes 310 and fixedwith adhesive. The wire-shaped grinding elements 32 are then aligned toa predetermined length, and the base end sides are thereafter aligned,as shown in FIG. 6(A). The base end sides of the wire-shaped grindingelements 32 are subsequently inserted into holes 60 in a die material 6formed to substantially the same size as the embedding holes 310 of theholder 31, as shown in FIG. 6(B), and in this state the base end sidesof the wire-shaped grinding elements 32 are fixed with silicon, epoxy,or another type of adhesive. As a result, rod assemblies 320 whose baseend sides are fixed with adhesive 71 are formed, as shown in FIG. 6(C).

Silicon, epoxy, or another type of adhesive 72, for example, issubsequently applied to the base end sides of the rod assemblies 320, asshown in FIG. 6(D); this is thereafter embedded in the embedding holes310 of the holder 32, as shown in FIG. 6(E); and in this state theadhesive 72 is hardened and the base end sides of the rod assemblies 320are fixed in the embedding holes 310 by bonding. Thus, in the presentembodiment a plurality of wire-shaped grinding elements 32 is bundled toform rod assemblies 320, which are embedded in the embedding holes 310of the holder 31 and fixed by bonding. Therefore, because a plurality ofrod assemblies 320 are batch manufactured, and these are successivelyinserted into the embedding holes 310 of the holder 31 and are fixed bybonding, the brush-shaped grindstone 3 can be manufactured withexcellent efficiency.

In the case of nylon filaments containing abrasive grain, the nylonfilaments containing abrasive grain can be prevented from unraveling byfolding the base end side to provide thickness and then embedding themin holes in the holder, but wire-shaped grinding elements 32 that useinorganic filaments break when folded, so the base end side cannot befolded as can nylon filaments or other materials. According to thepresent embodiment, however, the base end side of a bundle ofwire-shaped grinding elements 32 is hardened with adhesive 71 inadvance, and the base end side thereof has substantially the samediameter as the embedding holes 310, so with the rod assemblies 320embedded in embedding holes 310, the rod assemblies 320 do not fallover. The productivity of the brush-shaped grindstone 3 can therefore beimproved. In addition, the wire-shaped grinding elements 32 do notunravel, because the base end sides of the wire-shaped grinding elements32 are hardened with adhesive 71.

Embodiment 2

FIGS. 7(A) and (B) are, respectively, a diagram and a bottom view thatschematically depict the polisher brush related to embodiment 2 of thepresent invention.

In the present embodiment, a discoid projecting portion 50 that projectsto the external peripheral side is attached to the lower end side of thespindle 25 with screws 55, screw stops, or the like so as to allow easyremoval, as shown in FIGS. 7(A) and (B). The other features of thisstructure are the same as embodiment 1, and are therefore omitted fromthe description.

In the present embodiment, when the wire-shaped grinding elements 32attempt to escape to the external peripheral side, they bump against theinterior surface of the peripheral wall 20 of the brush case 2 and areheld back, and when the elements attempt to escape to the interiorperipheral side, they bump against an external peripheral surface of theprojecting portion 50 disposed on the spindle 25 and are held back. As aresult, there is no leeway that allows easy escape between thewire-shaped grinding elements 32 positioned on the external peripheralside and the wire-shaped grinding elements 32 positioned on the interiorperipheral side. The situation in which the wire-shaped grindingelements 32 positioned on the interior peripheral side become lessabrasive can therefore be avoided because no difference in rigidity isexhibited between the wire-shaped grinding elements 32 positioned on theexternal peripheral side and the wire-shaped grinding elements 32positioned on the interior peripheral side. The working precision canalso be improved because the wire-shaped grinding elements 32 areuniformly abraded. Since no variation occurs in the length (strandlength) of the wire-shaped grinding elements 32 from the holder 31, thechange in grindability and conformability due to this effect is reduced,so the working precision is stable.

The holder 31 can be removed from the spindle 25 merely by removing theprojecting portion 50 because the projecting portion 50 is attached witha screw 55 to the spindle 25 so as to allow easy removal. When thewire-shaped grinding elements 32 become worn out, the work of replacingthe wire-shaped grinding elements 32 and the holder 31 with new ones cantherefore easily be performed.

Embodiment 3

FIGS. 8(A) and (B) are, respectively, a diagram and a bottom view thatschematically depict the polisher brush related to embodiment 3 of thepresent invention.

In the present embodiment, a projecting portion 50 that projects to theexternal peripheral side at the lower end side is attached to the lowerend surface of the spindle 25 with screws 55, screw stops, or the likeso as to allow easy removal, as shown in FIGS. 8(A) and (B); a pluralityof protrusions 51 extended in a radial manner toward the externalperipheral side are further formed on an external peripheral side ofthis projecting portion 50; and wire-shaped grinding elements 32 areevenly positioned between these protrusions 51. The other features ofthis structure are the same as embodiment 1, and are therefore omittedfrom the description.

In the present embodiment, when the wire-shaped grinding elements 32attempt to escape to the external peripheral side, they bump against theinterior surface of the peripheral wall 20 of the brush case 2 and areheld back, and when the elements attempt to escape to the interiorperipheral side, they bump against the external peripheral side of theprojecting portion 50 disposed on the spindle 25, escape is restrained,and the range of escape is narrowed by the protrusions 51. As a result,there is no difference in the extend of escape between the wire-shapedgrinding elements 32 positioned on the external peripheral side and thewire-shaped grinding elements 32 positioned on the interior peripheralside. The situation in which the wire-shaped grinding elements 32positioned on the interior peripheral side become less abrasive cantherefore be avoided because no difference in rigidity is exhibitedbetween the wire-shaped grinding elements 32 positioned on the externalperipheral side and the wire-shaped grinding elements 32 positioned onthe interior peripheral side. The working precision can also be improvedbecause the wire-shaped grinding elements 32 are uniformly abraded.Since no variation occurs in the length (strand length) of thewire-shaped grinding elements 32 from the holder 31, the change ingrindability and conformability due to this effect is reduced, so theworking precision is stable.

Furthermore, the variation in the rigidity of the wire-shaped grindingelements 32 can be reduced in the peripheral direction as well becausethe wire-shaped grinding elements 32 can be prevented from escaping inthe peripheral direction by the protrusions 51.

The holder 31 can be removed from the spindle 25 merely by removing theprojecting portion 50 because the projecting portion 50 is attached witha screw 55 to the spindle 25 so as to allow easy removal. When thewire-shaped grinding elements 32 become worn out, the work of replacingthe wire-shaped grinding elements 32 and the holder 31 with new ones cantherefore easily be performed.

Embodiment 4

FIGS. 9(A) and (B) are, respectively, a diagram and a bottom view thatschematically depict the polisher brush related to embodiment 4 of thepresent invention.

In the present embodiment, a cylindrical body 520 comprising a pluralityof protrusions 52 in a form of blades extended in a radial manner towardthe external peripheral side is attached to the lower end surface of thespindle 25 with screws 55, screw stops, or the like so as to allow easyremoval, as shown in FIGS. 9(A) and (B), and wire-shaped grindingelements 32 are evenly positioned between these protrusions 52. Theother features of this structure are the same as embodiment 1, and aretherefore omitted from the description.

In the present embodiment, when the wire-shaped grinding elements 32attempt to escape to the external peripheral side, they bump against theinterior surface of the peripheral wall 20 of the brush case 2 and areheld back. When the wire-shaped grinding elements 32 attempt to escapeto the interior peripheral side, they bump against the externalperipheral surface of the spindle 25, escape is restrained, and therange of escape is narrowed by the protrusions 52. As a result, there isno difference in the extend of escape between the wire-shaped grindingelements 32 positioned on the external peripheral side and thewire-shaped grinding elements 32 positioned on the interior peripheralside. The situation in which the wire-shaped grinding elements 32positioned on the interior peripheral side become less abrasive cantherefore be avoided because no difference in rigidity is exhibitedbetween the wire-shaped grinding elements 32 positioned on the externalperipheral side and the wire-shaped grinding elements 32 positioned onthe interior peripheral side. The working precision can also be improvedbecause the wire-shaped grinding elements 32 are uniformly abraded.Since no variation occurs in the length (strand length) of thewire-shaped grinding elements 32 from the holder 31, the change ingrindability and conformability due to this effect is reduced, so theworking precision is stable.

Furthermore, the variation in the rigidity of the wire-shaped grindingelements 32 can be reduced in the peripheral direction as well becausethe wire-shaped grinding elements 32 can be prevented from escaping inthe peripheral direction by the protrusions 52.

The holder 31 can be removed from the spindle 25 merely by removing thecylindrical body 520 because the cylindrical body 520 comprisingblade-shaped protrusions 52 is attached with a screw 55 to the spindle25 so as to allow easy removal. When the wire-shaped grinding elements32 become worn out, the work of replacing the wire-shaped grindingelements 32 and the holder 31 with new ones can therefore easily beperformed.

Embodiment 5

FIG. 10 is an exploded perspective view depicting the state in which thepolisher brush related to embodiment 5 is disassembled into the brushcase and the brush-shaped grindstone.

The polisher brush in the present embodiment has fundamentally the sameconfiguration as embodiment 1, and differs only in the configuration ofthe guide holes formed in the peripheral wall of the brush case.Portions having common functions have the same key symbols and areomitted from the description.

As shown in FIG. 10, the polisher brush 1 of the present embodimentcomprises the cylindrical metal brush case 2 with the connecting shaft21 for driving on the upper portion, the brush-shaped grindstone 3 whoseupper portion is inserted into this brush case 2, and screws 41 and 42for fixing this brush-shaped grindstone 3 in a predetermined positioninside the brush case 2. The brush-shaped grindstone 3 comprises a largenumber of wire-shaped grinding elements 32, and the cylindrical metalholder 31 for collectively holding the base end sides of thesewire-shaped grinding elements 32.

In the present embodiment as well, a pair of screw holes 36 and 37 isformed in the peripheral wall of the holder 31 in point-symmetricalpositions on the opposite sides of the axis line L.

On the peripheral wall 20 of the brush case 2, guide holes 26′ and 27′extended in the form of a groove in a direction diagonal to thedirection of the axis line L thereof are formed in point-symmetricalpositions on the opposite sides of the axis line L. Here, the guideholes 26′ and 27′ extend in a direction diagonal about 20° to thedirection of the axis line L, for example.

In the present embodiment as well, when assembling a polisher brush 1using the brush-shaped grindstone 3 and the brush case 2, the spindle 25is fitted in the axle hole 30 of the holder 31, the upper portion (onthe side of the holder 31) of the brush-shaped grindstone 3 is insertedinside the brush case 2 in the same manner as embodiment 1, the screws41 and 42 are thereafter passed through the guide holes 26′ and 27′ fromthe external peripheral side of the brush case 2, as described withreference to FIGS. 5(C) and (D), and the screws 41 and 42 arerespectively screwed into the screw holes 36 and 37 of the holder 31. Atthis point, the screws 41 and 42 are tightened until the leading endportions of the axle portions of the screws 41 and 42 make contact withthe external peripheral surface of the spindle 25. As a result, theholder 31 is fixed onto the spindle 25 of the brush case 2 by way of thescrews 41 and 42 inside the brush case 2.

At this point, the screws 41 and 42 are shallowly screwed into the screwholes 36 and 37 of the holder 31 through the guide holes 26′ and 27′ ofthe brush case 2, and, in this state, the position of the brush-shapedgrindstone 3 inside the brush case 2 can be adjusted in the direction ofthe axis line L by moving the brush-shaped 3 inside the brush case 2 inthe direction of the axis line L. The protruding length of the free end33 of the wire-shaped grinding elements 32 at the lower end portion 29of the brush case 2 can be adjusted, so the stiffness of the wire-shapedgrinding elements 32, in other words, the grindability andconformability can be optimized.

Here, the guide holes 26′ and 27′ for guiding the brush-shapedgrindstone 3 extend toward the peripheral wall 20 of the brush case 2 ina direction diagonal to the axis line L. As a result, the angle to thedirection of the axis line L of the guide holes 26′ and 27′ is set toθ°, and if the brush-shaped grindstone 3 was moved the distance L1 alongthe guide holes 26′ and 27′, the brush-shaped grindstone 3 essentiallymoves the distance L2=(L1/cos θ), even though it was moved the distanceL1 along the guide holes 26′ and 27′. In other words, when one wants tomove the brush-shaped grindstone 3 the distance L2 in the direction ofthe axis line L, the brush-shaped grindstone 3 need only to be moved thedistance L1=(L2/cos θ) along the guide holes 26′ and 27′.

Therefore, according to the present invention, the protruding length ofthe free end 33 of the brush-shaped grindstone 3 can easily and quicklybe adjusted to an optimal state because the position of the brush-shapedgrindstone 3 in the direction of the axis line L in the brush case 2 caneasily be adjusted in small increments. Thus, because the stiffness ofthe wire-shaped grinding elements 32, in other words, the grindabilityand conformability can easily and quickly be adjusted, high quality burrremoval and polishing work can be performed.

When the brush-shaped grindstone 3 does not easily move inside the brushcase 2, according to the present embodiment, brush-shaped grindstone 3can still be moved smoothly because force is applied to the brush-shapedgrindstone 3 in the direction in which the brush-shaped grindstone 3rotates about the axis line L.

The protruding portion 50 described in embodiment 2 may be disposed onthe spindle 25 in the polisher brush 1 in the present embodiment.

The flat surfaces 250, 260, and 270 described in embodiment 1 may bedisposed on the spindle 25 or on the peripheral wall 20 of the brushcase 2 in the present embodiment as well.

Other Embodiment 1

The brush-shaped grindstone 3 related to the above embodiments is anexample in which the bottom surface of the cylindrical holder 31 servesas the grinding element holding surface 311, and a plurality ofembedding holes 310 are formed in a single line about the axis line L ofthe center of rotation, but the present invention may also be applied toa brush-shaped grindstone 3A in which rod assemblies 320 are embedded inthe embedding holes 310 that comprise a plurality of round holes formedin a plurality of lines; for example, two lines, about the axis line Lof the center of rotation in the grinding element holding surface 311comprising the bottom surface of the cylindrical holder 31, as shown inFIG. 11(A).

The present invention may also be applied to brush-shaped grindstones 3Band 3C in which rod assemblies 320 are embedded in embedding holes 310.The holes comprise a plurality of round holes formed about the axis lineL of the center of rotation in the grinding element holding surface 311,itself comprising the side surface of the cylindrical or columnar holder31, as shown in FIGS. 11(B) and (C).

Although this is not shown in the drawings, the present invention mayfurther be applied to a brush-shaped grindstone in which rod assembliesare embedded in embedding holes that comprise a plurality of round holesformed at irregular positions about the axis line of the center ofrotation in the grinding element holding surface of holders of variousshapes.

Other Embodiment 2

The embodiments described above entail the use of rod assemblies 320 inwhich the base end portions of a plurality of the wire-shaped grindingelements 21 are roundly bundled, but it is also possible to use rodassemblies 320 in which the base end portions of a plurality ofwire-shaped grinding elements 21 are flatly aligned, as shown in FIG.12(A).

In this case, a plurality of embedding holes 310 in the form of groovesare formed on the grinding element holding surface 311 comprising thebottom surface of the cylindrical holder 31, rod assemblies 320 in whichthe base end portions of the plurality of wire-shaped grinding elements21 are flatly aligned are formed, and the base end sides of these rodassemblies 320 may be fixed with adhesive in the embedding holes 310 ofthe holder 31, in the manner of the brush-shaped grindstone 3E shown inFIG. 12(B).

A plurality of embedding holes 310 in the form of grooves are formed onthe grinding element holding surface 311 comprising the side surface ofthe cylindrical or columnar holder 31, rod assemblies 320 in which thebase end portions of the plurality of wire-shaped grinding elements 21are flatly aligned are formed, and the base end sides of these rodassemblies 320 may be fixed with adhesive in the embedding holes 310 ofthe holder 31, in the manner of the brush-shaped grindstone 3F shown inFIG. 12(C).

Other Embodiment 3

The above embodiments were described with reference to an example inwhich the brush-shaped grindstone 3 was wire-shaped grinding elements 32formed such that the composite yarn composed of inorganic filaments suchas alumina filaments was impregnated and hardened with a binder resin,but the present invention may also be applied to a polisher brushwherein the brush-shaped grinding material 3 is wire-shaped grindingelements 32 obtained such that nylon (resin) that contains siliconcarbide or other abrasive grains is molded into filaments, or to apolisher brush wherein brass or stainless steel wire-shaped grindingelements 32 are used as the brush-shaped grinding material 3. Carbonnanotubes may also be admixed into the binder resin when the wire-shapedgrinding elements 32 are constructed.

In the above embodiments, the composite yarn with the substantiallycircular cross-section was used in the wire-shaped grinding elements 32without twisting the inorganic filaments, but a configuration obtainedby twisting the inorganic filaments into a composite yarn may also beadopted. When inorganic filaments are twisted into the composite yarn,an advantage is obtained whereby the leading ends of the wire-shapedgrinding elements 32 are resistant to splitting.

In the above embodiments, the cross-sections of the wire-shaped grindingelements 32 assume a configuration in which the shape is substantiallycircular, but a configuration in which the cross-section is flat mayalso be adopted. When the cross-sections of the wire-shaped grindingelements are flat, plugging is minimal during burr removal and polishingin comparison with the configuration in which the shape of thecross-section is substantially circular. An advantage is obtainedwhereby flexibility is exhibited in the wire-shaped grinding elements,and breaking is minimized. When the cross-sections of the wire-shapedgrinding elements are flat, the ratio of flatness represented by L/T ispreferably 1.6 to 15, but is more preferably in a range of 1.6 to 10,where L is the length of the cross-section, and T is the breadth of thecross-section.

Industrial Applicability

As described above, according to the present invention, a plurality ofwire-shaped grinding elements are bundled to form rod assemblies, andthese are embedded in the embedding holes of the holder and fixed bybonding. As a result, a plurality of rod assemblies are batchmanufactured, and these are successively inserted into the embeddingholes of the holder and fixed. The brush-shaped grindstone can thereforebe manufactured with excellent efficiency.

1. A manufacturing method for a brush-shaped grindstone having aplurality of wire-shaped grinding elements, each element being formedsuch that a composite yarn composed of inorganic filaments isimpregnated and hardened with a resin, and a holder for holding base endside portions of the wire-shaped grinding elements on a grindstoneholding surface, comprising steps of: forming a plurality of embeddingholes that open on the grindstone holding surface in isolated positions;forming rod assemblies by bringing a plurality of wire-shaped grindingelements together; and embedding base end side portions of the rodassemblies in the embedding holes and fixing them with adhesive.
 2. Themanufacturing method for a brush-shaped grindstone according to claim 1,wherein round holes are formed as the embedding holes in the holder, andwherein a plurality of wire-shaped grinding elements are roundly bundledto form each of the rod assemblies.
 3. The manufacturing method for abrush-shaped grindstone according to claim 1, wherein grooves are formedas the embedding holes in the holder, and wherein a plurality ofwire-shaped grinding elements are flatly aligned to form each of the rodassemblies.
 4. The manufacturing method for a brush-shaped grindstoneaccording to claim 1, wherein the inorganic filaments are twisted in thecomposite yarn.
 5. The manufacturing method for a brush-shapedgrindstone according to claim 1, wherein the wire-shaped grindingelements have a flat cross-section.
 6. A brush-shaped grindstonemanufactured according to the method as defined in claim
 1. 7. Apolisher brush having: a brush-shaped grindstone as defined in claim 6;a cylindrical brush case; and screws for fixing the holder on aninterior side of the brush case so that free ends of the wire-shapedgrinding elements protrude from lower end portion of the brush case;wherein the brush case is formed with a spindle extending inside thebrush case along an axial direction thereof, and with guide holesextending in the form of grooves in a peripheral wall of the brush casealong the axial direction thereof; wherein the holder is formed with anaxle hole in which the spindle is fitted, and with screw holes thatextend from an external peripheral surface of the holder to the axlehole; and wherein the screws are secured in the screw holes so as to beattached to the external peripheral side of the brush case and to passcompletely through the guide holes in a state in which leading endportions of screw shafts come in contact with an external peripheralsurface of the spindle.
 8. The polisher brush according to claim 7,wherein a surrounding portion where the leading end portions of thescrew shafts come in contact with the external peripheral surface of thespindle, is a flat surface.
 9. The polisher brush according to claim 7,wherein guide holes extend parallel to the axial direction on theperipheral wall of the brush case.
 10. The polisher brush according toclaim 7, wherein the guide holes extend in a direction diagonal to theaxial direction on the peripheral wall of the brush case.
 11. Thepolisher brush according to claim 7, wherein a projecting portion thatprojects toward the external peripheral side of the spindle is attachedto the spindle at its lower end side.
 12. The polisher brush accordingto claim 7, wherein a projecting portion that projects toward theexternal peripheral side of the spindle is attached to the spindle atits the lower end side; a plurality of protrusions extending radiallytoward the external peripheral side are formed on an external peripheralside of the projecting portion; and the wire-shaped grinding elementsare evenly positioned between the protrusions.
 13. The polisher brushaccording to claim 7, wherein a plurality of protrusions extendingradially toward the external peripheral side are attached to thespindle, and the wire-shaped grinding elements are evenly positionedbetween said protrusions.